Retirement Plans - Schedule of Plan Asset Measured on a Recurring Basis (Details) - Pension Plan - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	$ 4,068	$ 4,400	$ 4,363
Fair Value, Recurring
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	4,068	4,400
Fair Value, Recurring \| Federal government securities
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	1,448	1,508
Fair Value, Recurring \| Bonds and debentures
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	1,512	1,696
Fair Value, Recurring \| Corporate stock
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	226	181
Fair Value, Recurring \| Venture capital and buyout partnerships
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	$ 446	$ 554
Defined Benefit Plan, Plan Assets, Fair Value by Hierarchy and NAV [Extensible Enumeration]	Fair Value Measured at Net Asset Value Per Share	Fair Value Measured at Net Asset Value Per Share
Fair Value, Recurring \| Real estate funds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	$ 26	$ 30
Defined Benefit Plan, Plan Assets, Fair Value by Hierarchy and NAV [Extensible Enumeration]	Fair Value Measured at Net Asset Value Per Share	Fair Value Measured at Net Asset Value Per Share
Fair Value, Recurring \| Collective trust and other funds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	$ 370	$ 382
Defined Benefit Plan, Plan Assets, Fair Value by Hierarchy and NAV [Extensible Enumeration]	Fair Value Measured at Net Asset Value Per Share	Fair Value Measured at Net Asset Value Per Share
Fair Value, Recurring \| Other assets/(liabilities)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	$ 40	$ 49
Fair Value, Recurring \| Fair Value, Inputs, Level 1, Level 2, and Level 3
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	3,186	3,385
Fair Value, Recurring \| Quoted Prices in Active Markets for Identical Inputs (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	220	176
Fair Value, Recurring \| Quoted Prices in Active Markets for Identical Inputs (Level 1) \| Federal government securities
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	0	0
Fair Value, Recurring \| Quoted Prices in Active Markets for Identical Inputs (Level 1) \| Bonds and debentures
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	0	0
Fair Value, Recurring \| Quoted Prices in Active Markets for Identical Inputs (Level 1) \| Corporate stock
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	220	176
Fair Value, Recurring \| Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	2,966	3,209
Fair Value, Recurring \| Significant Other Observable Inputs (Level 2) \| Federal government securities
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	1,448	1,508
Fair Value, Recurring \| Significant Other Observable Inputs (Level 2) \| Bonds and debentures
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	1,512	1,696
Fair Value, Recurring \| Significant Other Observable Inputs (Level 2) \| Corporate stock
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	6	5
Fair Value, Recurring \| Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	0	0
Fair Value, Recurring \| Significant Unobservable Inputs (Level 3) \| Federal government securities
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	0	0
Fair Value, Recurring \| Significant Unobservable Inputs (Level 3) \| Bonds and debentures
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	0	0
Fair Value, Recurring \| Significant Unobservable Inputs (Level 3) \| Corporate stock
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	0	0
Fair Value, Recurring \| Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	$ 842	$ 966